Declarative Visualization in Python

Altair is a declarative statistical visualization library for Python, based on
Vega-Lite.

With Altair, you can spend more time understanding your data and its meaning.
Altair’s API is simple, friendly and consistent and built on top of the
powerful Vega-Lite visualization grammar. This elegant simplicity produces
beautiful and effective visualizations with a minimal amount of code.

Note: Altair and the underlying Vega-Lite library are under active
development; new plot types and streamlined plotting interfaces will be
added in future releases. Please stay tuned for
developments in the coming months! – October 2016

The key idea is that you are declaring links between data columns to encoding channels, such as the x-axis, y-axis, color, etc. and the rest of the plot details are handled automatically.
Building on this declarative plotting idea, a surprising number of useful plots and visualizations can be created.

More examples are available in the Example Gallery, or you can work
through one of the Altair Tutorials. The full documentation listing
is available below.